1. Field of the Invention
The present invention relates to a leakage detecting device and more particularly to a leakage detecting device for cylinders of a vehicle engine.
2. Description of Related Art
After a time of use, gaskets or seals on the cylinders of a vehicle engine become worn, cracked etc. Due to the wear of the gasket or the seal, the waste gases such as carbon monoxide will leak out from the cylinder and some of them will flow into the water tank of the vehicle. Therefore, the leakage of the cylinders of the vehicle engine is detected from the water tank by means of measuring the density of the carbon monoxide in the water tank. With reference to FIG. 5, a conventional way to detect the density of the carbon monoxide in the water tank (60) uses a balloon sampler (50). The sampler (50) comprises a balloon and a sampling tube attached to and communicating with the balloon. When the balloon is compressed, the air in the balloon will be pressed out from the sampling tube. When the balloon is released, the air at the outer circumstance will be sucked into the balloon through the tube. Accordingly, the sampler can sample the air in the water tank (60) through an opening (61) in the tank (60). After sampling air from the water tank (60), the air in the balloon is released into a container (70) contained with a reagent for carbon dioxide. The density of the carbon dioxide will be measured by means of the change in color of the reagent, and the leakage condition of the cylinders of the vehicle engine will be observed.
However, the fresh air at the surroundings will also be sucked into the balloon while the sampler (50) is sampling the air from the water tank (60). The detecting result applied by the conventional way with the balloon sampler (50) is not precise.
To overcome the shortcomings, the present invention tends to provide a leakage detecting device to mitigate or obviate the aforementioned problems.
The main objective of the invention is to provide a leakage detecting device for cylinders of a vehicle engine that can precisely detect the leakage of the cylinders by sampling the water from the water tank of the vehicle. To achieve the above objective, the leakage detecting device has a cover, a first cup and a second cup. The cover is mounted on the opening of the water tank and has a through hole. The first cup is connected to the cover and communicates with the through hole in the cover. A connecting tube has a first end extending through the closed end of the first cup and connected to the through hole in the cover and a second end extending into the first cup. A first cap is mounted in the first cup and surrounds the second end of the connecting tube. The first cap has a closed end separated from the second opening end of the connecting tube and the opening end separated from the closed end of the first cup. The second cup is mounted on an opening end of the first cup. A guide tube is mounted on the closed end of the second cup and communicates with a bottom hole defined in the closed end of the second cup, and the guide tube has a top opening end. A second cap is mounted in the second cup and surrounds the top opening end of the guide tube. The second cap has a closed end separated from the top opening end of the guide tube and an opening end separated from the closed end of the second cup.